ARM: iop: convert sched_clock() to use new infrastructure

Convert iop platforms to use the new sched_clock() infrastructure for
extending 32bit counters to full 64-bit nanoseconds.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/Kconfig

@@ -992,6 +992,7 @@ config ARCH_ACORN
 config PLAT_IOP
 	bool
 	select GENERIC_CLOCKEVENTS
+	select HAVE_SCHED_CLOCK
 
 config PLAT_ORION
 	bool

arch/arm/plat-iop/time.c

@@ -24,6 +24,7 @@
 #include <linux/clockchips.h>
 #include <mach/hardware.h>
 #include <asm/irq.h>
+#include <asm/sched_clock.h>
 #include <asm/uaccess.h>
 #include <asm/mach/irq.h>
 #include <asm/mach/time.h>
@@ -50,15 +51,21 @@ static struct clocksource iop_clocksource = {
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
+static DEFINE_CLOCK_DATA(cd);
+
 /*
  * IOP sched_clock() implementation via its clocksource.
  */
 unsigned long long notrace sched_clock(void)
 {
-	cycle_t cyc = iop_clocksource_read(NULL);
-	struct clocksource *cs = &iop_clocksource;
+	u32 cyc = 0xffffffffu - read_tcr1();
+	return cyc_to_sched_clock(&cd, cyc, (u32)~0);
+}
 
-	return clocksource_cyc2ns(cyc, cs->mult, cs->shift);
+static void notrace iop_update_sched_clock(void)
+{
+	u32 cyc = 0xffffffffu - read_tcr1();
+	update_sched_clock(&cd, cyc, (u32)~0);
 }
 
 /*
@@ -144,6 +151,8 @@ void __init iop_init_time(unsigned long tick_rate)
 {
 	u32 timer_ctl;
 
+	init_sched_clock(&cd, iop_update_sched_clock, 32, tick_rate);
+
 	ticks_per_jiffy = DIV_ROUND_CLOSEST(tick_rate, HZ);
 	iop_tick_rate = tick_rate;